Generally speaking, relatively little attention has hitherto been paid to the design of backs for office chairs. A typical chair back is a relatively flat upholstered structure with some degree of lateral curvature so that the sides of the back to some extent wrap around the sides of the body of a person seated in the chair.
In the field of automotive seating, seats for sports cars have been developed that wrap quite far around the sides of the body of a person in the seat, so as to laterally restrain the person against high loads when the car is cornering. In some case, the seat has a relatively narrow central portion and a pair of "bolsters" or "wings" that extend outwardly from opposite sides of the back to snugly embrace the user. An example of a seat of this type is disclosed in Canadian patent application No. 2,210,366 (Coffield).
An object of the present invention is to provide a chair, particularly (though not necessarily) an office chair, which has a back structure designed to provide some lateral support to a user of the chair, while allowing for body movement.